Definition
PHP
PHP is a server-side scripting language widely used for the Web — reportedly powering around 72% of sites. It is commonly embedded directly into HTML: variables start with
$, string concatenation uses the dot., and code sits between<?php … ?>tags.
Superglobals
Superglobal associative arrays
Superglobals are built-in associative arrays available throughout a PHP script. The most important ones are:
Array Contents $_GETparameters of the query string (URL) $_POSTparameters submitted in a POSTrequest body$_SESSIONvalues stored in the current [[Knowledge/HTTP Cookie $_COOKIEcookies sent by the client $_FILESmetadata of uploaded files Because they come straight from the client,
$_GETand$_POSTare the usual entry points for SQLi, command, path-traversal, and SSRF attacks, and must never be used unsanitised.